Summary: Design and Implementation Tradeo#s for
Wide­Area Resource Discovery
JEANNIE ALBRECHT, DAVID OPPENHEIMER, and AMIN VAHDAT
University of California, San Diego
and
DAVID A. PATTERSON
University of California, Berkeley
We describe the design and implementation of SWORD, a scalable resource discovery service for
wide­area distributed systems. In contrast to previous systems, SWORD allows users to describe
desired resources as a topology of interconnected groups with required intra­group, inter­group,
and per­node characteristics, along with the utility that the application derives from specified
ranges of metric values. This design gives users the flexibility to find geographically distributed
resources for applications that are sensitive to both node and network characteristics, and allows
the system to rank acceptable configurations based on their quality for that application.
Rather than evaluating a single implementation of SWORD, we explore a variety of architec­
tural designs that deliver the required functionality in a scalable and highly­available manner.
We discuss the tradeo#s of using a centralized architecture as compared to a fully decentralized
design to perform wide­area resource discovery. To summarize our results, we found that a cen­
tralized architecture based on 4­node server cluster sites at network peering facilities outperforms
a decentralized DHT­based resource discovery infrastructure with respect to query latency for all